VERTIPH is a visual language designed to aid in the development of image
processing algorithms on FPGAs (Field Programmable Gate Arrays). We justify the
use of a visual language for this purpose, and describe the key parts of
VERTIPH. One aspect of importance is how to clearly and efficiently represent a
pipeline of processors, and in particular distinguish a pipeline from the
simpler serial or parallel structures. This paper develops a number of pipeline
representations, discussing the rationale behind and limitations associated
with each representation. The culmination of this development is the Sequential
Pipeline with Detailed Bars, visually an efficient and unambiguous
representation.

Four and twenty tern chicks plotted in a pie: a graphical interface for
predicting chick ages with a confidence estimate

We present a computer interface that represents the age of chicks as
dynamically-generated chromatic bands on a set of plots drawn on conventional
Cartesian axes. The chromatic information allows us to increase the number of
variables on the plot from two to three, so that the user can infer a chick's
age from two easily obtained body measurements. The overall image contains a
number of realisations of a non-linear multivariate hierarchical model of chick
growth; the model is parametric, and each plot is produced by running the model
with a different combination of parameters. Even with chromatic banding, the
plots can be difficult to interpret because, when many plots overlap, later
plots obscure earlier ones. To reveal the information hidden thereby, the
interface incorporates a component that allows the user to generate a pie-chart
showing all the ages that fall within a 95% confidence ellipse around any point
on the plot.

Previous research has examined the effect of display size on distance
estimation in static images and demonstrated that display size affects
participant's distance estimate task performance. Several other researches have
also reported similar outcomes. Examination of the experimental setups of these
early researchers suggests that other factors may also contribute to the
effect. In this paper, we report our investigations that extend the earlier
research by examining the contribution of other factor such as viewing distance
and physiological cues. By fixing the viewing distance of the observer, our
research indicates that viewing distance (and physiological cues) does
influence distance estimation. The large magnitude of effect size for display
size factor however suggested that display size still constitutes a major
influence in distance estimation task.

Although the 2D desktop metaphor has been the dominating paradigm of user
interfaces for over two decades, 3D models of interaction are becoming more
feasible due to advances in computer output hardware and software technology.
However, conventional input devices such as a mouse or track-pad generally
restrict direct manipulation interaction to a 2D paradigm. More sophisticated
3D input devices such data-gloves have been available for some time, but these
tend to be expensive or restrictive in their use. In this paper we describe a
simple and inexpensive single camera-based video input system which allows 3D
interaction with existing computer application using bare hands.

It is virtually envisioned that in the near future home-service robots will
be assisting people in their daily lives. While a wide spectrum of utility of
home-service robots has been proposed, i.e., cleaning, surveillance or
go-and-fetch jobs, usability studies of the home-service robots have been less
undertaken. This paper explores the usability issues, in particular, a
map-based user interface for instructing home-service robots in the home
environment. It focused on how the different map representation of the
co-located environment would affect task performance of locating the
home-service robots. The effectiveness of the map-based human-robot interface
was thus analysed according to the dimensionality of the map, the location
information of the elements in the co-located workspace. The experimental
results showed that task performance was varied by the different map
representation, providing a better understanding of what characteristics of the
map representation were able to effectively support the human operator in
instructing the home-service robots in the home environment.

To allow the immense volume of spatial data currently available to be used
effectively, people need intelligent query tools that are simple and intuitive.
Standard query tools have a number of serious usability limitations, as they
often rely solely on numerical approaches when dealing with spatial
information. The qualitative reasoning community has addressed this issue, by
providing powerful formalisms based on the way that humans deal with spatial
information, however, integrating these methods into numerical systems raises a
number of new Computer-Human Interaction (CHI) problems. This paper addresses
three key CHI challenges when combining qualitative and numerical methods: (1)
managing the subjective, ambiguous nature of qualitative terms, (2) providing a
powerful, yet simple query system, and (3) effectively visualising a complex,
fuzzy qualitative query solution. A qualitative GIS called TreeSap is
presented, which demonstrates that, with the use of CHI principles, query tools
can be both powerful and accessible to non-expert users.

Ink annotation is a common method for recording feedback on a paper
document. However, reviewing code on paper is difficult due to its non-linear
nature. This project extends existing research ideas to develop a digital ink
annotation tool within an Integrated Development Environment (IDE). The aim is
to provide code reviewers with an effective tool for directly commenting on
code within the IDE. We describe scenarios where ink annotation would provide
benefits, along with requirements and our implementation of the Rich Code
Annotation Tool (RCA).

A central activity involved in the user-centred design process is usability
evaluation. Cost-effective evaluation tools to fully support usability
evaluations however, are still limited. The aim of this work is to introduce a
web-based, resource-supported, interactive evaluation toolkit called R-IDE,
which guides evaluation planners through the various activities involved in
planning and conducting usability evaluations. The IDE stages of the DECIDE
framework provide the basis for the design of this toolkit, which currently
supports two evaluation methods: heuristic evaluation for websites and standard
questionnaires. This paper describes the design, development, evaluation and
future potential of this toolkit.

The representation of GUIs as documents is a technological trend that has
been present for some years, but is only now about to significantly change the
way in which most user interfaces are developed. This paper examines this
change, explains the reasons behind it and the concepts involved. It compares
the old fashioned way of programming user interfaces as code units with the
document-based paradigm, explaining why the latter is preferable. Furthermore,
it discusses how the document-based paradigm can be extended to a very
comprehensive and well defined customization approach for GUIs, the
document-oriented approach, which supports the paradigms of end-user
development and robust content.

Software cost estimation techniques are used to provide a useful measure of
the complexities, efforts, and costs involved in system development. Despite
three decades of research on software cost estimation, the research community
has yet to provide a viable model for End-User Development (EUD) environments.
This is both surprising and significant as EUD has been estimated to account
for somewhere between 80-95% of all personal software development activities
worldwide. As EUD is predominantly idiosyncratic, self-determined and
opportunistic, existing cost estimation techniques are either inappropriate,
overly complex or insufficient. In response, we present a novel "personal cost"
estimation model for EUD. This model reflects key features of non-professional
programming, and provides a qualitative evaluation of personal cost as
motivation, and hence, likely project success.

Focussing on a standard pattern form: the development and evaluation of MUIP

A framework for the tool, MUIP (Management of User Interface Patterns), has
been developed based on the relevant literature and a survey of existing
pattern tools. The framework supports the following features: pattern
authoring, manipulating forces, browsing patterns, searching patterns,
versioning and customising patterns, relating patterns, manipulating
collections and importing or exporting patterns. Patterns are described using
the standard pattern form (PLML). An enhanced version of PLML, called PLML
vl.2, has been developed so that pattern contents can be organised more
effectively. Guided by this framework, a specification of a comprehensive
pattern management system for manipulating dissimilar pattern collections was
developed and a prototype implemented accordingly. A formal evaluation
confirmed the usefulness of the prototype.

First experiences with a mobile information system aimed at supporting
reflective exploration suggest that the device's visualization of past
activities and, in particular, the routes taken helps participants orientate
themselves and plan the next steps of their explorative activity. Drawing from
insect navigation research we provide a preliminary explanation of some
intriguing behavioral observations made during deploying mExplore as a
technology probe. We also speculate about using mobile information systems to
help visitors conduct "learning flights" and thus help them better understand
the environment they are exploring by helping them recognize the varying visual
impressions of landmarks from different perspectives. This work thus links in a
unique way work on mobile information systems in tourism and other
information-oriented areas to insect navigation research and (human-oriented)
research into landmark salience and its use in ego-centric navigation.

This paper reports on the evaluation of a digitally-augmented exhibition on
the history of modern media and our experiences with the methodic approach
employed. As a central element of this exhibition visitors can buy a smartcard
that enables them to store collected or self-created data in a 'digital
backpack', which can be accessed via internet as a personalized souvenir. We
have evaluated the exhibition, visitors' perceptions and usage of the card
using a multi-method strategy complementing quantitative data-analysis with
qualitative, ethnographic methods. This paper focuses on visitors' use and the
perceived utility of the smartcard, and our experiences with using
automatically generated data from interaction logfiles for analyzing visitor
behavior, and with the multi-method strategy.

We present the results of a study that compares a range of depth cues for an
augmented reality (AR) stakeout application. AR stakeout is the process of
placing a real pole on a virtual marker on the ground. Such an application is
for example relevant for construction work or surveying. In AR stakeout,
interaction takes place at a distance of about 2m from the eye; a distance that
has been neglected by AR depth perception research. We compared the performance
of six different AR depth cue conditions at two different accuracy
requirements. Subjective preferences were strongly in favour of "cast circle",
a depth cue introduced in this paper, while there was no significant difference
in performance between the conditions. An analysis of the movement patterns
indicated that the participants' targeting strategy relied on kinesthetic
rather than visual feedback. These movement patterns provide a vantage point
for future strategies of targeting support.

Virtual reality (VR) and augmented reality (AR -- overlaying virtual objects
onto the real world) offer interesting and wide spread possibilities to study
different components of human behaviour and cognitive processes. One aspect of
human cognition that has been frequently studied using VR technology is spatial
ability. Research ranges from training studies that investigate whether and/or
how spatial ability can be improved by using these new technologies to studies
that focus on specific aspects of spatial ability for which VR is an efficient
investigational tool. In this paper we first review studies that used VR
technologies to study different aspects of spatial ability. Then results and
findings will be presented from one of the first large-scale studies (215
students) that investigated the potential of an AR application to train spatial
ability.

This paper intends to review different affordances of two media on mobile
phones, i.e., voice calls vs. text messages. The two empirical studies of
mobile media use showed that Habermas' theory could partially explain this
aspect.

Previous work discussed a model of cognitive distance with the novel
concepts of "tech bias", "velocity" and "inertia". This paper presents a
revised version of the model of human factors involved, and describes a pilot
study that suggests the model presented allows for a very high degree of
confidence in predicting the effect a user's familiarity with a problem domain
and specific implementation will have on their perception of the directness of
the user interface.